It is around 16.2 m (53 ft) tall[3] with a circumference at breast height of 4.15 m (14 ft).[1][4]
It was planted in 1783–1784, during the reign of Queen Maria I, and since 1820 it has been harvested over 20 times. 1991 was a particularly prolific year, as it yielded over 1,200 kg (2,646 lb) of cork, producing more than 100.000 cork stoppers, more than what an average cork tree would produce in its lifetime.[1][5]
The name 'Whistler Tree' comes from the whistling sound of the birds that land on its branches.[6]
In 2000 the tree was almost taken down, along with 411 other cork oaks, as an illegal urban expansion took place. By 2001 the law was reformed to better protect the oaks.[7]
Views of Sobreiro Monumental - the whistling cork oak